My thoughts are only way she can possibly ever learn accountability
McLean's Hospital is a psychiatric institution. People get admitted when the have debilitating emotional crisis or breakdown or try to kill themselves... .
I think you thinking more in terms of a residential treatment program - where people go to reprogram their approach to life.
People (all people) typically seek / or are motivated to treatment after an some failure or loss in life to resolve problems they perceive.
I think this article an video will help you get this in perspective.
Tell us what you think.
https://bpdfamily.com/content/how-to-get-borderline-into-therapy